The different stakes of male and female birth control. This gave me a touch of FLAMES ON THE SIDE OF MY FACE: "A recent clinical trial of an injectable hormone contraceptive for men showed super promising results: It was 96 percent effective at preventing pregnancy, which it did by lowering sperm counts. Unfortunately, the trial was discontinued early by an independent committee, which determined that the side effects were such that 'the risks to the study participants outweighed the potential benefits.' The side effects in question? 'Mood changes, depression, pain at the injection site, and increased libido.'" UM.